RT Journal Article SR Electronic T1 Importance of Q waves in early diagnosis of hypertrophic cardiomyopathy JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 1993 OP 1994 DO 10.1136/heartjnl-2011-300456 VO 97 IS 23 A1 Usha Rao A1 A Agarwal YR 2011 UL http://heart.bmj.com/content/97/23/1993.abstract AB